I think you have already come with a lot of ideas. I am going to take a more general approach.
The airport is like a strategic resource for kindred, and also for any power trying to take control of the city.
Kindred politics
As you have said, the airport is a potential entry point for enemy kindred (sabbat, anarchs, enemies of the prince,...). For that reason, the primogeniture can demand some degree of collaboration or even control of the airport. If the characters fail controlling the kindred entrance, the primogeniture could take action to transfer the airport to someone more fitted.
Of course the characters can expect many favours in return of the responsabilities they have.
Not only official Camarilla enemies are interesting. Many kindred would exchange favours in return of knowing about the movements of their rivals (who could be respected Camarilla members).
Other powers
Not only Kindred, but anyone who wants control of the city would put their attention on the airport. They can range from mortal politicians, police, and criminals to hunters, werewolves or mages.
Characters should be careful not to be easily tracked by these groups, or they could have trouble and put the Masquerade at risk.
As a personal approach, I won't use the Technocracy. Vampires are supposed to not know about it, and I think they don't mix well in Vampire stories. But that's my personal opinion, you can do as you please.
Owning is not controlling
Notice that the characters who own the airport are not the only ones that could have influence on it. Hundreds work in an airport, and the characters can't control them. Other power players can have spies or in extreme cases saboteurs without too much effort. So, don't warn them, but you can introduce some competition.
Ghouls are expensive
I have read that they are planning to make a huge amount of ghouls. Please, see that having ghouls is not an easy task.
First, they may need permission to make such a quantity. Ghouls are technically a Masquerade breach. Of course, given their great responsibility, characters can justify it to the primogeniture.
Second, they must feed as many ghouls. Count how many ghouls they have; that is how many blood points they must spend per month.
Third, ghouls are volatile. A ghoul can sometimes do incredible things to get their domitor's attention. With dozens of ghouls, the competition can be brutal. Having to manage so much emotional problems can be insane.
So, I'd consider having only a few important ghouls, and control other people via domination, presence or mundane ways (money is always effective).
It has been a long time since I played Vampire, but - not only is it possible to do a group creation followed by individual preludes - it's the best way to do it.
You will probably need to have a gap in time between the creation session and the first Prelude. There will likely be some tailoring needed once you know the characters. But that's not a huge problem most of the time.
Character Creation for the Mechanics and the Meta
The Character Creation session should be used as a chance to have players become familiar with the system if they aren't already, and to discuss a few details of their characters to ensure they will work together and not have too much overlap.
You also have players discuss meta elements. Perhaps two players want to play rivals. They can discuss these details during this process, decide why they're going to be rivals.
Work up the full character, but I'd suggest telling players that no choices are final. Give them a chance to make changes once they better understand the mechanics and the setting.
During this part of the process, you needn't discuss more than the bare minimum of setting details. You know, just enough to make sure the characters will all fit within the premise. "You're all newly embraced kindred in the crazy world of high finance in the 1980s. Think American Psycho meets Vampire Diaries." Just enough to ensure the characters will work in your premise, and no more.
Prelude for the Setting and Story
Once you have the characters set, you can run individual preludes. This is the stage where you begin to introduce setting and story elements, and it can be run as free of mechanics as you and your players are comfortable with.
It need not be less interesting just because the characters are mortals. But making a story compelling does depend a lot on the GM. If you make the journey memorable, it will be awesome.
The last time I played Vampire, my GM did it this way. I built my Assamite, and then we roleplayed his journey from boy, to man, to trained assassin, right up to the scene where his mentor bites him on the neck and then hangs him up on a meathook. It was horrifying, and gut churning, but it was never dull. Along the way, my GM hinted at what it meant for the future.
You mentioned Initiations in Dogs in the Vineyard. As a GM, I've used this idea in preludes for other World of Darkness games (and other games) to help make them memorable. Players make characters, and then I ask them to ask a question we will answer during the prelude. This helps keep them engaged as they search for their answers.
This way will preserve nice balance between player agency and GM mystery. Players have freedom to create the characters they envision within the limits of the premise, but the GM doesn't reveal too many secrets too soon. I've played it, and run it, and it works well.
Best Answer
"Released" means it is being conjured anywhere beyond the thaumaturge's own palm.
As per the v20 rules, the number of successes determines the accuracy of the placement of the flame. You need to declare the size of the flame (determines difficulty) and the desired placement before rolling (determines successes required).
If you want it to appear in your hand, it requires only one success. (Using anything above a palm sized flame in this case is not recommended...) Five successes means you can place it anywhere within your line of sight. It is indicated in v20 that, as a rule of thumb, you need one success per 10 yards of distance. Once the roll is successfull, there is no need for throwing or otherwise placing the flame, it immediately appears at the desired location.
When it is in your palm, it will not harm anyone including yourself, nor can it be thrown. It will function as a light and a tool to scare the crap out of other kindred. If placed anywhere else, it immediately becomes an active flame that causes damage and rötschrek. At that point, the thaumaturge no longer controls the fire and cannot quench it.
Dodging is not described in the book, but to me it seems that it can be dodged like a ranged attack if the victim has inits over the caster and knows what lure of flames is. (It's kind of hard to determine that someone is going to set you on fire if he is only looking at you.)